1. Field of the Invention
This invention relates generally to the treatment of allergy and in particular to the treatment of allergy with the peptide thymopentin.
2. Description of the Art
U.S. Pat. No. 4,190,646 describes the pentapeptide thymopentin, having the sequence H-ARG-LYS-ASP-VAL-TYR-OH. This pentapeptide has activity similar to the long chain polypeptide known as thymopoietin, disclosed in U.S. Pat. Nos. 4,002,740 and 4,077,949. Both thymopoietin and thymopentin selectively stimulate the differentiation of T lymphocytes. The U.S. Pat. No. 4,190,646 discloses that thymopentin is expected to have utility in the areas of thymic function and immunity. The various specific diseases or conditions which could be treated by thymopentin are described in this patent. Since the invention of thymopentin, considerable effort has been expended on studying its effect on a variety of immune-related disorders. A collection of some recent work in this area is contained in Survey of Immunologic Research, Volume 4, Supplement 1, 1985, entitled "Thymopentin in Experimental and Clinical Medicine". This volume is completely devoted to thymopentin and its relevance to treatment of immune disorders.
Sale of thymopentin (under the trademark "TIMUNOX") was commenced in Italy in the spring of 1985 for treatment of primary immune deficiency.
Although the Supplement referred to above evidences effectiveness of thymopentin in treatment of herpes and rheumatoid arthritis, there is no suggestion that it would be effective in treatment of allergy.
Nearly one in every ten persons in the United States suffers from symptomatic atopic disease, the most common being allergic rhinitis. Bronchial asthma and atopic dermatitis occur less frequently. Other types of allergic disorders include anaphylaxis, urticaria and periarteritis nodose. Immunologically, allergy is classified as a type I hypersensitivity reaction to environmental antigens (allergens) in genetically-susceptible individuals who produce IgE antibodies to these allergens. These IgE antibodies (fixed to mast cells) react with the allergen, triggering the release of histamine, leucotrienes, eosinophil chemotatic factor (ECF) and other mediators of allergic hypersensitivity. The action of these mediators on blood vessels, smooth muscles, and secretory glands is responsible for the clinical manifestation and pathologic features of the disease.
Conventional therapies for hay fever and other forms of allergic rhinitis typically include drugs such as antihistamines or corticosteroids, which act on the mediators, rather than the root cause of the disease. These drugs have various side effects which render them less than ideal, especially for long-term use. The other conventional therapy is immunotherapy, normally consisting of a program of desensitization injections to the appropriate allergens. Although such treatments attack the cause of the disease, they are time-consuming, costly, and painful. The responsible allergen(s) must be determined, typically by a series of skin tests, following which the patient must be subjected to the desensitization injections.
Significant benefit would be afforded those suffering from allergic rhinitis and other allergic disorders if a therapy could be made available which treated the root cause of the disease without the discomfort and inconvenience of desensitization injections.